TONY JONES, PRESENTER: It took more than 20 years to build and cost nearly $30 billion. Now Japan's state-of-the-art nuclear fuel reprocessing plant is about to open. The plant in the far north of the country will be capable of turning spent nuclear fuel into eight tonnes of plutonium each year. The Japanese say the weapons grade plutonium will only be used for power generation, but that hasn't soothed American concerns about the security of the stockpile and the possible effect on a regional arms race. North Asia correspondent Mark Willacy was given an exclusive look inside the Rokkasho nuclear complex.

MARK WILLACY, REPORTER: With 17,000 tonnes of spent nuclear fuel sitting in pools like this across the country, Japan wants to reprocess it and use it again to generate electricity. It spent $28 billion building this reprocessing plant here at Rokkasho, which is capable of turning this used fuel into eight tonnes of plutonium every year.

TAKASHI AKASAKA, JAPAN NUCLEAR FUEL LTD (voiceover translation): We started constructing the plant 20 years ago and it'll be completed in October. We need this plant because Japan doesn't have its own energy resources.

MARK WILLACY: But the Obama administration in Washington fears this plant may fuel a race for nuclear technology and even weapons in North Asia.

This is the place that Japan stores its most toxic nuclear waste. In fact, just a couple of metres beneath me are 1,400 canisters of it.

KEIKO KIKUKAWA, ANTI-NUCLEAR CAMPAIGNER (voiceover translation): Our village has become a dump for Japan's nuclear waste. If there was an accident, it would be catastrophic.

MARK WILLACY: Rokkasho was once a poor farming and fishing area, but now thousands of residents are employed at the plant, which even before it's begun operation has earned this small village council more than $400 million in taxes and subsidies.

KENJI FURUKAWA, ROKKASHO MAYOR (voiceover translation): If the project is stopped, it will be a death blow to this community, so we've asked the national government to let it continue.

MARK WILLACY: The Government is almost certain to do that, despite fears it'll create a pile of plutonium theoretically capable of being used to build thousands of nuclear weapons.

TAKASHI AKASAKA (voiceover translation): Plutonium is controlled very strictly by law and is mixed with uranium so it can't be used in nuclear weapons. We also have United Nations nuclear inspectors stationed at the plant 24 hours a day.

MARK WILLACY: But that doesn't reassure opponents of the reprocessing plant, who are quick to point out that the biggest shareholder this project is TEPCO, the operator of the shattered Fukushima nuclear complex.